Trust me, I know how you feel. Had a beautiful future in another profession lined up... but you'll get thru it. I broke down with a week to go, decided that my days needed to be less intense. Looking back, the test was very doable. If you're aiming for a perfect score maybe not, but otherwise you'll be alright. Try and relax if you can... remember to have some time to yourself.
In the end, remember its just a test... just another hoop you have to jump thru to be a kick ass doc!